Re-entry catheter

ABSTRACT

Total occlusions are crossed by passing a guidewire or other penetrating wire from a point proximal to the occlusion into a subintimal space between the intimal layer and adventitial layer of the blood vessel wall. The wire is advanced to a point distal to the occlusion and thereafter deflected back into the blood vessel lumen, typically using a deflecting catheter which is advanced over the guidewire after it has been positioned within the subintimal space. After the guidewire is returned to the blood vessel lumen, the deflecting catheter may be withdrawn and the guidewire is available for introduction of other interventional and diagnostic catheters.

RELATED APPLICATIONS

This is a continuation of Ser. No. 09/765,777 now U.S. Pat. No.6,511,458 filed Jan. 19, 2001, which is a continuation of Ser. No.09/440,308 now U.S. Pat. No. 6,235,000, filed Nov. 17, 1999, which is adivisional of Ser. No. 09/006,563 U.S. Pat. No. 6,231,546, filed Jan.13, 1998.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical devices, kits, andmethods. More particularly, the present invention relates to systems andprocedures for crossing chronic total occlusions in blood vessels withguidewires and subsequently performing angioplasty, atherectomy,stenting, or other treatments.

Cardiovascular disease is a leading cause of mortality worldwide.Cardiovascular disease can take many forms, and a variety of specificinterventional and pharmaceutical treatments have been devised over theyears with varying levels of success.

A particularly troublesome form of cardiovascular disease results when ablood vessel becomes totally occluded with atheroma or plaque, referredto as a chronic total occlusion. Until recently, chronic totalocclusions have usually been treated by performing a bypass procedurewhere an autologous or synthetic blood vessel is anastomoticallyattached to locations on the blood vessel upstream and downstream of theocclusion. While highly effective, such bypass procedures are quitetraumatic to the patient.

Recently, catheter-based intravascular procedures have been utilized totreat chronic total occlusions with increasing success. Catheter-basedintravascular procedures include angioplasty, atherectomy, stenting, andthe like, and are often preferred because they are much less traumaticto the patient. Before such catheter-based treatments can be performed,however, it is usually necessary to cross the occlusion with a guidewireto provide access for the interventional catheter. In some instances,crossing the occlusion with a guidewire can be accomplished simply bypushing the guidewire through the occlusion. The guidewire remains inthe blood vessel lumen and provides the desired access path. In manycases, however, the guidewire inadvertently penetrates into thesubintimal space between the intimal layer and the adventitial layer ofthe blood vessel as it attempts to cross the occlusion. Once in thesubintimal space, it is very difficult and in many cases impossible todirect the guidewire back into the blood vessel lumen. In such cases, itwill usually be impossible to perform the catheter-based interventionand other, more traumatic, procedures may have to be employed.

For these reasons, it would be desirable to provide methods, kits, andapparatus which facilitate crossing a chronic total occlusion in a bloodvessel with a guidewire. In particular, it would be desirable to providecatheters, guides, or other apparatus which could be used with aconventional or specialized guidewire to direct or redirect theguidewire from the subintimal space back into the blood vessel lumenafter the guidewire has entered such space. Such methods and apparatusshould be useful in coronary arteries as well as other blood vessels andshould be capable of being performed with or without imaging from withinor adjacent to the blood vessel. The apparatus for achieving theseobjective should be of simple construction and be capable of being usedin a straight-forward, generally fool-proof manner. At least some ofthese objectives will be met by the invention described hereinafter.

2. Description of the Background Art

Catheters having side guidewire entry ports spaced proximally from theirdistal tips are described in U.S. Pat. Nos. 5,464,395; 5,413,581;5,190,528; 5,183,470; 4,947,864; and 4,405,314. Catheters and methodsfor forming lateral penetrations through tissue to and from bloodvessels past total occlusions are described in U.S. Pat. Nos. 5,443,497;5,429,144; 5,409,019; 5,287,861; WO 97/13463; and WO 97/13471.

SUMMARY OF THE INVENTION

According to the present invention, methods are provided for crossingtotal occlusions in blood vessels. While the methods are particularlybeneficial for the treatment of coronary artery disease, they are alsouseful in the treatment of other arteries and veins, such as thetreatment of peripheral vascular diseases.

The total occlusions are crossed by first forming a track from a lumenin the blood vessel into a subintimal space between an intimal layer andan adventitial layer of the blood vessel. The track is formed so that itextends from a location proximal of the total occlusion to a locationwhich is distal to the total occlusion. A passage is then formed fromthe track back into the blood vessel lumen at the distal location. Inthe specific embodiments, the track is formed by advancing a wirethrough the blood vessel lumen into the subintimal space, typically byadvancing the wire until it encounters the total occlusion. Bycontinuing to advance the wire, it will usually pass into the subintimalspace and can be further advanced to the desired distal location. Afterthe wire is located distally to the total occlusion, it is typicallydeflected from the track back into the blood vessel lumen.

In the exemplary methods, the wire is deflected using a deflectingcatheter. Typically, the deflecting catheter is advanced over a proximalend of the wire and advanced into the track within the subintimal space.The wire and the deflecting catheter are then manipulated so that thewire is deflected laterally through the intimal layer back into theblood vessel lumen. Such deflecting catheters are also useful insupporting the wire as it is advanced into and/or through the track,i.e. the catheter can enhance the “pushability” of the wire when it isadvanced forward through any resisting material. Specific designs forsuch deflecting catheters are described in detail below. Alternatively,the wire which is initially positioned within the track in thesubintimal space may be withdrawn through the deflecting catheter andexchanged for a second wire or other device suitable for penetratingthrough the intimal layer back into the blood vessel lumen. It will beappreciated that the wires and/or deflecting and other catheters may befreely exchanged over or through one another in a conventional matterwithout departing from the present invention.

It will usually be necessary to determine when the wire and/ordeflecting catheter are positioned distal to the total occlusion so thatthe wire may be returned to the blood vessel lumen beyond saidocclusion. Most simply, such position determination can be made byfluoroscopically imaging the blood vessel in a conventional manner.Alternatively or additionally to such fluoroscopic imaging,intravascular imaging, e.g. intravascular ultrasonic imaging (IVUS), anda variety of optical imaging modelities, such as optical coherencetomography (OCT), may be employed. For example, an ultrasonic imagingguidewire may be used to initially access the subintimal space and/ormay be exchanged for the wire which is used to access the subintimalspace. An imaging guidewire present in the subintimal space may readilydetect the presence or absence of occluding material within the bloodvessel lumen. When the transition from occluding material to lack ofoccluding material is detected, it is known that the position of theguidewire has advanced beyond the total occlusion.

After the passage is formed back from the track into the blood vessellumen and a wire is in place across the total occlusion, the wire isavailable for use as a guidewire in positioning interventional anddiagnostic catheters across the total occlusion. Most commonly,interventional catheters will be positioned across the total occlusionfor treating the occlusion. Exemplary interventional catheters includeangioplasty balloon catheters, rotational atherectomy catheters,directional atherectomy catheters, stent-placement catheters, and thelike.

In a preferred aspect of the methods of the present invention, the wiredeflecting step will comprise deflecting a cannula from the subintimalspace back into the blood vessel lumen and thereafter passing the wirethrough a path defined by the cannula, typically by a lumen within thecannula. Usually, the cannula will be advanced over the wire after thewire is disposed within the subintimal space, and the cannula-deflectingstep will comprise advancing a resilient (pre-formed) curved end of thecannula from a constraining lumen into the blood vessel lumen.Alternatively, the wire-deflecting step may comprise advancing adeflecting catheter over the wire which has been advanced into thesubintimal space. A cannula may then be advanced through a lateralopening of the deflecting catheter and penetrated through the intimallayer to define a path for the wire back into the blood vessel lumen.Steerable and other actively deployed cannulas may also be used.

The present invention further provides kits comprising a wire-deflectingcatheter having a lumen or mechanism capable of laterally deflecting awire. The kit will further comprise instructions setting forth any ofthe methods described above. Optionally, the kit may further comprisethe wire which is used for penetrating the subintimal space and/or backinto the blood vessel lumen. The kit will usually still further comprisea package for containing both the wire deflecting catheter and theinstructions, and optionally the additional wire(s). Suitable packagesinclude pouches, trays, tubes, boxes, and the like. The instructions maybe printed on a separate package insert or may be printed in part or inwhole on the packaging itself. Usually, the components of the kit withinthe package will be sterilized by conventional procedures.

Apparatus according to the present invention comprise wire-deflectionsystems. Exemplary wire-deflection systems usually comprise thewire-deflecting catheter which includes a catheter body and a deflectingcannula. The catheter body will have a proximal end, a distal end, andat least one lumen extending through at least a distal portion thereof.The lumen will have a distal opening and a lateral opening. The cannulaalso has a proximal end, a distal end, and at least one lumen extendingthrough a distal portion thereof. The distal portion of the cannula willhave a pre-formed, resilient curve. The cannula will be slidablydisposed within the lumen of the catheter body to assume (a) astraightened configuration when the cannula is proximally retractedwithin the catheter body lumen and (b) a curved configuration when thecannula is extended laterally through the lateral opening of thecatheter body. In this way, the cannula can be selectively deflectedthrough the intimal layer of the blood vessel according to the preferredmethods described above. The system may further comprise a wireconfigured to pass through the cannula lumen. The wire may be aconventional guidewire, but will more typically be a wire having asharpened distal tip intended particularly for penetrating the intimallayer of the blood vessel wall. Optionally, the wire may furthercomprise an imaging means such as an ultrasonic imaging means. Thecatheter body will typically have a fluoroscopically visible marker nearits distal end. The marker will be configured to permit visualdetermination of the rotational orientation of the distal end of thecatheter body when viewed in a two-dimensional fluoroscopic image. Thecatheter body will usually be reinforced to enhance torsional rigidity,and may further comprise a distal nose cone wherein the distal andlateral openings are defined within the nose cone. The distal end of thecannula will usually be pre-formed in a smooth curve which may extendover an arc in the range from 15° to 135°, usually from 45° to 90°. Thepre-formed curve may have a radius in the range from 0.5 mm to 15 mm,usually from 2 mm to 10 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a coronary artery showing theintimal layer, the medial layer, and the adventitial layer.

FIG. 2 is a schematic illustrations of a total occlusion within thecoronary artery of FIG. 1, shown in full section.

FIGS. 3A-3D illustrate the method of the present invention for crossinga total occlusion with a wire using a deflecting catheter.

FIGS. 3BB illustrates an alternate guidewire advancement step for themethod of FIGS. 3A-3D.

FIG. 4 illustrates a first embodiment of the distal end of a deflectingcatheter suitable for use in the methods of the present invention.

FIG. 5 illustrates a second embodiment of the distal end of a deflectingcatheter useful in the methods of the present invention.

FIG. 6 illustrates a third embodiment of the distal end of a deflectingcatheter useful in the methods of the present invention.

FIG. 7 illustrates a presently preferred embodiment for thewire-deflecting catheter and system of the present invention.

FIGS. 8 and 9 are detailed, cross-sectional views of the distal end ofthe catheter of FIG. 7, illustrating an internal cannula in a retractedand advanced configuration, respectively.

FIG. 10 is a schematic illustration of a proximal hub of the catheter ofFIG. 7.

FIGS. 11A and 11B illustrate a configuration for rotationally keying theproximal end of the catheter of FIGS. 7-10.

FIG. 12 illustrates a configuration for rotationally keying the distalend of the catheter of FIGS. 7-10.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

Referring to FIG. 1, a normal (non-diseased) artery A comprises a lumenL and an arterial wall having a number of layers. The tissue of thearterial wall is collectively referred to herein as the extraluminalspace within the artery or blood vessel. The innermost layer of thearterial wall is referred to herein as the intimal layer I whichincludes the endothelium, the subendothelial layer, and the internalelastic lamina. A medial layer M is concentrically outward from theintimal layer, and an adventitial layer AL is the outermost layer.Beyond the adventitial layer AL lies the extravascular tissue. As usedhereinafter, the region between the intimal layer I and the adventitiallayer AL, generally including the medial layer M, will be referred to asthe subintimal space. It is the subintimal space through which thewires, deflecting catheters, and other catheter of the present inventionwill pass when crossing a total occlusion.

Referring now to FIG. 2, a total occlusion TO within the artery A isillustrated. Total occlusion TO may comprise atheroma, plaque, thrombus,and/or other occluding materials normally associated with cardiovasculardisease. By “total” occlusion, it is meant that the occluding materialoccludes substantially the entire lumen L of the artery or other bloodvessel so that blood flow through the vessel is substantially stopped.The present invention will usually be used with patients where thetotally occluded artery is not immediately life threatening since thetissue distal to the occlusion will receive oxygenated blood fromcollateral arteries. Usually, however, the blood supply will beinsufficient and it will be desirable to treat the occlusion by anintravascular intervention, such as angioplasty, atherectomy, stenting,or the like, to restore blood flow through the affected vessel.

The method of the present invention will be described with reference toFIGS. 3A-3D. These figures represent an upper portion of the artery ofFIG. 2. As seen in FIG. 3A, a wire 10 is advanced through the lumen ofthe artery until it encounters the total occlusion TO. At that time, itis possible that the wire 10 will advance through the occlusion withoutdeflecting into the blood vessel wall. Should that occur, subsequentrepositioning of the guidewire according to the methods of the presentinvention may not be necessary. More usually, however, the wire 10 willadvance into the subintimal space within the medial layer M, as shown inFIG. 3A. The intimal layer I and adventitial layer AL together define a“tissue plane” through which the wire will naturally pass as the wire ispushed distally from its proximal end. The wire 10 will continue toadvance until its tip passes beyond the distal end of the totalocclusion TO, as shown in FIG. 3B. The tip could axially advance wellbeyond the total occlusion until advancement is ceased.

FIG. 3B shows the guidewire 10 advancing without support. In someinstances, however, the guidewire 10 may encounter significantresistance as it enters and/or passes through the space between theintimal layer I and adventitial layer AL. If resistance is encountered,the deflection, catheter 20 may be used to support and enhance the“pushability” of the guidewire 10 by advancing the catheter to alocation just proximal of the distal tip of the guidewire, as shown inFIG. 3B. The guidewire 10 and catheter 20 may then be advancedsequentially, e.g. advancing the guidewire a short distance followed byadvancing the catheter, and so on.

According to the present invention, however, once the wire 10 has itsdistal tip positioned beyond the total occlusion TO, deflecting catheter20 may be advanced over the wire 10, by coaxial introduction over theproximal end of the wire, until it approaches the total occlusion, alsoas shown in FIG. 3B. The deflecting catheter 20 is then further advancedover the wire 10 until its distal tip also extends beyond the totalocclusion TO, as illustrated in FIG. 3C. The deflecting catheter 20 willinclude some mechanism for laterally deflecting the wire 10 so that itmay pass back in a radially inward direction through the intimal layer Iback into the blood vessel lumen L. The deflection mechanism may take avariety of forms as described below. As shown in FIG. 3C, a lateral port22 is provided. The wire 10 may be retracted so that its distal tip liesproximally of the port 22 and then advanced distally so that the wirepasses laterally outwardly through the port and back into the bloodvessel lumen, as shown in FIG. 3D.

In order to optimize performance of this method, it is usually desirableto assure that the distal tip of the wire 10 and the deflecting port 22(or other deflecting mechanism) of the deflecting catheter 20 areproperly positioned beyond the total occlusion TO without being advancedexcessively beyond the end of the total occlusion. Typically, it will bedesirable to position the deflecting mechanism at from 0 cm to 2 cmbeyond the distal end of the total occlusion TO, preferably from 0 cm to0.5 cm. As discussed above, such positioning can in some instances beperformed using conventional fluoroscopic imaging. For example, in someinstances it may be sufficient to provide suitable radiopaque markers onthe wire and on the deflecting mechanism of the deflecting catheter 20permitting visual positioning of the tip via fluoroscopy. Often,however, it will be desirable to provide ultrasonic or other imaging ator near the total occlusion. In one approach, wire 10 may be providedwith ultrasonic imaging so that the presence and absence of theoccluding material may be detected as the wire is advanced passed thetotal occlusion TO. Alternatively, the deflecting catheter 20 may beprovided with such ultrasonic imaging, e.g. in the form of a phasedarray located near the distal tip (not shown). Ultrasonic imagingguidewires are described in the patent literature. See, e.g. U.S. Pat.No. 5,095,911, the full disclosure of which is incorporated herein byreference. As yet another alternative, an imaging guidewire may beadvanced to the region of the total occlusion TO in a direction oppositeto that of the wire 10 and catheter 20. In this way, the imagingguidewire need not advance through the total occlusion, but could stilldetect advancement of the catheter and/or guidewire, particularly ifultrasonically opaque components were provided on either or both of thecatheter and wire. In yet another alternative, an ultrasonic imagingcatheter or guidewire could be positioned in a vein adjacent to thearterial occlusion site, allowing imaging of the entire occluded regionwhile the guidewire is advanced there through. Other imaging modalities,such as optical coherence tomography (OCT) (see U.S. Pat. Nos.5,321,501; 5,459,570; 5,383,467; and 5,439,000) fluorescence imaging(see U.S. Pat. Nos. 4,718,417; and 5,106,387) and Raman spectroscopy (WO92/18008), may also be employed.

A second desirable feature of the method of the present invention willbe rotational positioning of the deflecting catheter 20. It will beappreciated that the direction of deflection is usually selective, andtherefore it will be desirable to aim the deflecting mechanism from thesubintimal space back toward the arterial or other blood vessel lumen L.If the catheter 22 is provided with ultrasonic imaging, such imaging canbe used for rotationally positioning the distal tip of the catheter. Thecatheter will be rotationally rigid so that rotation of its proximal endmay position the distal end. By then detecting the presence of the bloodvessel lumen, the deflecting port 22 or other deflecting mechanism canbe properly positioned. In an alternative embodiment, as illustratedbelow in connection with the exemplary catheter, a rotationally specificfluoroscopic marker may be provided on the catheter 20. The marker willbe such that by observing the two-dimensional image of the marker byfluoroscopic imaging, the rotational direction of the catheter tip canbe determined.

Referring now to FIGS. 4-6, exemplary deflecting mechanisms for thedeflecting catheters of the present invention will be described. In FIG.4, the distal end of the catheter 30 has a distal port 32, a lateralport 34, and a passive deflecting mechanism 36. The catheter 30 may beadvanced over the proximal end of a wire so that the wire passes overthe deflecting mechanism 36 and back into the main lumen of the catheter30. The catheter 30 may then be advanced over the wire until the distaltip enters the subintimal space and approaches the distal end of thewire. By retracting the distal end of the wire within the lumen ofcatheter 30 so that its distal tip is proximal to the deflectingmechanism 36, subsequent distal advancement of the wire will engage theproximal surface of the deflecting mechanism and cause the wire to bedeflected laterally through lateral port 34.

A first active deflecting mechanism is illustrated in FIG. 5. There,catheter 40 has a distal port 42 and a lateral port 44. Rather than apassive deflecting mechanism, catheter 40 includes an axiallytranslatable cannula 46 having a resilient, pre-formed distal tip whichmay be advanced through port 44, as shown in broken line. The cannula 46has a lumen which provides a guide path for the wire.

Catheter 50 illustrated in FIG. 6 is similar to catheter 40 in FIG. 5,except that no lateral port is provided. Instead, a cannula 52 having apre-formed distal end may be advanced and retracted out of a distal port54 of the catheter 50 so that its distal end can assume a laterallydeflected shape, as shown in broken line. It will be appreciated thatthese three embodiments are intended to be exemplary only. A widevariety of other passive and active deflecting mechanisms could beprovided on deflecting catheters for use in the methods of the presentinvention.

Referring now to FIGS. 7-10, a presently preferred exemplary deflectingcatheter 100 constructed in accordance with the principles of thepresent invention will be described. The deflecting catheter 100comprises a catheter body 102 having a distal end 104 and a proximal end106. Catheter body 102 includes a single lumen 108 (FIGS. 8 and 9), anda deflecting housing 110 secured to the distal end 104 thereof. Anactuator hub 112 is secured to the proximal end 106 of catheter body102, and an axially translatable cannula is disposed within lumen 108.The cannula 114 has a sharpened tip 116, typically formed from a metal,hard plastic, composite, or the like, optically being radiopaque.Alternatively or additionally, it may be desirable to provide at leastone separate radiopaque marker or the cannula at or near its distal endto facilitate visualization under fluoroscopic imaging. A distal length118 of the cannula 114 is pre-formed in a curved shaped, as best seen inFIGS. 7 and 9. A rotationally specific radiopaque marker 120 is mountednear the distal end of catheter body 102. As illustrated, the marker hasa generally U-shaped configuration so that the rotational position ofthe distal end of the catheter body 102 will be apparent when the markeris observed in a two-dimensional fluoroscopic image.

As with catheter 40 in FIG. 5, the purpose of catheter 100 is tolaterally deflect the distal tip of the cannula 114 through a lateralopening 122 in the deflector housing 110. The deflector housing 110 alsoincludes a distal port 124 to permit introduction of the catheter 100over the proximal end of a guidewire GW, as illustrated in FIG. 8 inbroken line. The guidewire GW will pass through the distal port 124 andinto the distal end of the cannula 114 and travel through a lumen ofcannula 114 all the way to the proximal end of the catheter 100. Thedistal length 118 of cannula 114 will be straightened and deflected byaxially retracting and advancing the cannula between the configurationshown in FIG. 8 and FIG. 9, respectively.

Referring now to FIG. 10, the actuator hub 112 comprises a pair ofcoaxial, telescoping tubes 130 and 132. The outer telescoping tube 132is connected to a proximal end of cannula 114, typically by an adhesive134. A proximal fitting 136 is further attached to the proximal end oftube 132 so that the assembly of the cannula 114, tube 132, and fitting136 will move together as a unit through the hemostatic fitting 140 atthe proximal end of the hub 112. Hub 112 further includes a rotationalfitting 142 which permits the catheter body 102 to be rotated relativeto the hub body. The cannula 114 and catheter body 102 will berotationally coupled or “keyed” together to limit or prevent relativerotation, typically by keying within the hub and/or near the distal end,so that rotation of the catheter body causes a like rotation of thecannula as the catheter is rotationally positioned within a bloodvessel. A side branch 148 is provided on hub 112 to permit perfusionand/or infusion through the lumen 108 of catheter 102.

Keying at the proximal end of the catheter 100 can be achieved in avariety of ways. For example, the telescoping tubes 130 and 132 can beprovided with asymmetric, mating peripheral geometries, such as ovalcross-sections (FIG. 11A) or triangular cross-sections (FIG. 11B).Keying at the distal end can also be achieved in a number of ways, suchas providing the catheter body 102 with an asymmetric lumen 108 and thecannula 114 with a mating cross-section, e.g. a D-shaped cross-sectionas illustrated in FIG. 12. The ability to limit relative rotation of thecannula 114 within the catheter body 102 is advantageous since itassures that curved distal length 118 is properly oriented (usuallydirected radially outwardly) when the tip 116 emerges through theopening 122.

In use, catheter 100 will be advanced over guidewire GW while thecannula 114 is retracted, as shown in FIG. 8. Once the catheter isproperly positioned, cannula 114 may be distally advanced, as shown inFIG. 9. Distal advancement is achieved by forwardly advancing the sleeve132 in hub 136 relative to the remainder of the hub 112 so that thecannulas move forwardly within the lumen 108 of catheter body 102. Priorto advancing the cannula, the port 122 will be properly positioned sothat it is directed toward the blood vessel lumen by rotating catheterbody 102, typically using the rotational hub 142. Conveniently, thephysician will observe the marker 120 so that the lateral port 122 willbe directed in the proper radially inward direction. After the cannulahas been advanced into the blood vessel, the guidewire GW may then beadvanced into the lumen, the cannula 114 withdrawn proximally, and theentire catheter assembly then withdrawn from over the guidewire, leavingthe guidewire in place for introduction of other interventional and/ordiagnostic catheters.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the invention which is defined by the appendedclaims.

What is claimed is:
 1. A re-entry catheter for use in forming a pathwaybetween an extraluminal space within a blood vessel and a lumen of theblood vessel, comprising: a catheter body including a proximal end, adistal end, and at least one guide wire lumen configured to track over aguide wire to a treatment site; a catheter endpiece coupled to thedistal end of the catheter body, the catheter endpiece including alateral port in communication with the lumen, wherein the lateral portis proximal to the distal end of the catheter endpiece, the catheterendpiece further including a deflection mechanism in communication withthe lumen and the lateral port; and a working element having a proximalend and a distal end, wherein the distal end of the working element isconfigured to deploy through the lateral port for delivery from a firstvascular location within the extraluminal space to a second vascularlocation within the true lumen of the blood vessel.
 2. The cathetersystem of claim 1, wherein the working element includes a cannula havinga lumen.
 3. The catheter system of claim 1, wherein the working elementincludes a guide wire.
 4. The catheter system of claim 1, wherein theworking element includes a cannula and a guide wire, wherein the guidewire is slidably disposed within the cannula.
 5. The catheter system ofclaim 1, further comprising a distal port positioned at the distal endof the catheter endpiece.
 6. The catheter system of claim 1, wherein thedistal end of the working element includes a preformed resilient tip. 7.The catheter system of claim 1, further comprising a guide wire.
 8. Thecatheter system of claim 1, further comprising an active visualizationelement.
 9. The catheter system of claim 1, further comprising afluoroscopic marking system.
 10. A re-entry catheter for use in forminga pathway between an extraluminal space within a blood vessel and a truelumen of the blood vessel, comprising: a catheter body including aproximal end, a distal end, and at least one lumen configured to trackover a guide wire to a treatment site, wherein an inside diameter of thelumen is uniform; a catheter endpiece coupled to the distal end of thecatheter body, the catheter endpiece including at least one port incommunication with the lumen, and a working element having a proximalend and a distal end, wherein the distal end of the working element isconfigured to deploy through the port for delivery from a first vascularlocation within the extraluminal space to a second vascular locationwithin the true lumen of the blood vessel when the working element isadvanced distally through the port.
 11. The catheter system of claim 10,wherein the working element includes a cannula having a lumen.
 12. Thecatheter system of claim 10, wherein the working element includes aguide wire.
 13. The catheter system of claim 10, wherein the workingelement includes a cannula and a guide wire, wherein the guide wire isslidably disposed within the cannula.
 14. The catheter system of claim10, wherein the port is positioned at the distal end of the catheterendpiece.
 15. The catheter system of claim 10, wherein the port ispositioned proximal to the distal tip of the catheter endpiece.
 16. Thecatheter system of claim 10, wherein the at least one port includes afirst port positioned at the distal end of the catheter endpiece, and asecond port positioned proximal to the distal tip of the catheterendpiece.
 17. The catheter system of claim 10, wherein the distal end ofthe working element includes a preformed resilient tip.
 18. The cathetersystem of claim 10, further comprising a guide wire.
 19. The cathetersystem of claim 10, further comprising an active visualization element.20. The catheter system of claim 10, further comprising a fluoroscopicmarking system.
 21. The catheter system of claim 10, further comprisinga deflection mechanism in communication with the lumen and the least oneport.
 22. A re-entry catheter for use in forming a pathway between anextraluminal space within a blood vessel and a true lumen of the bloodvessel, comprising: a catheter body including a proximal end, a distalend, at least one lumen, and a distal termination, wherein the distaltermination includes an internal deflection mechanism in communicationwith the lumen and at least one lateral port; and a guide wire that isslidably disposed within the lumen and configured for deployment from afirst vascular location within the extraluminal space to a secondvascular location within the true lumen of the blood vessel using thelumen and the lateral port.
 23. The catheter system of claim 22, whereinthe catheter body is configured for use in peripheral vasculature. 24.The catheter system of claim 22, wherein the catheter body is configuredfor use in coronary vasculature.
 25. The catheter system of claim 22,wherein the guide wire is configured for use in peripheral vasculature.26. The catheter system of claim 22, wherein the guide wire isconfigured for use in coronary vasculature.
 27. The catheter system ofclaim 22, wherein the guide wire includes a sharpened distal tip. 28.The catheter system of claim 22, further comprising a visualizationdevice for use in identifying a re-entry location and positioning thelateral port towards the re-entry location.
 29. The catheter system ofclaim 28, wherein the guide wire includes the visualization device. 30.The catheter system of claim 28, wherein the catheter body includes thevisualization device.
 31. A re-entry catheter for use in forming apathway between an extraluminal space within a blood vessel and a truelumen of the blood vessel, comprising: a wire configured for advancinginto the extraluminal space to a location proximate to a target re-entrysite of a lumen of the blood vessel; a catheter body including at leastone distally positioned port, wherein an outside diameter of thecatheter body is uniform, the catheter body configured for advancingover the wire into the extraluminal space to the location proximate to atarget re-entry site; and a cannula configured to form a path from theextraluminal space to a second vascular location within the true lumenof the blood vessel, wherein the wire is retracted into the cannulafollowing placement of the catheter body at the location, wherein thecannula is configured for advancing through the at least one distallypositioned port of the catheter body and through the target re-entrysite to form a pathway from the extraluminal space within a blood vesselinto the true lumen of the blood vessel, and the guide wire is deliveredthrough the cannula to the second vascular location.
 32. A re-entrycatheter for use in forming a pathway between an extraluminal spacewithin a blood vessel and a lumen of the blood vessel, comprising: acatheter body including at least one guide wire lumen and at least onedistal port, wherein an inside diameter of the guide wire lumen isuniform, wherein a guide wire is positioned in the guide wire lumen andthe catheter body is configured to be advanced over the guide wire intothe extraluminal space to a re-entry target location of the blood vessellumen; and a visualization device for use in positioning the at leastone port of the catheter body towards the re-entry target location,wherein the catheter body is configured to deliver the guide wire fromthe extraluminal space to the blood vessel lumen when the guide wire isadvanced through the at least one port to form the pathway from theextraluminal space into the blood vessel lumen.
 33. A re-entry catheterfor use in forming a pathway between an extraluminal space within ablood vessel and a lumen of the blood vessel, comprising: a catheterbody including at least one lumen and at least one distal port, whereinan inside diameter of the lumen is uniform, wherein a guide wire ispositioned in the catheter body and the catheter body is configured tobe advanced over the guide wire into the extraluminal space to are-entry target location of the blood vessel lumen; a visualizationdevice configured to position the at least one distal port of thecatheter body towards the re-entry target location; a cannula slidablydisposed within the at least one lumen, wherein the cannula isconfigured to deploy from the at least one distal port of the catheterupon advancement and to generate a pathway from the extraluminal spaceinto the blood vessel lumen; and a guide wire positioned in the slidablydisposed cannula and configured for advancement through the pathwaycreated by the cannula and into the blood vessel lumen.